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Through their suggestive name, non-targeted methods (NTMs) do not aim at a predefined "needle in the haystack." Instead, they exploit all the constituents of the haystack. This new type of analytical method is increasingly finding applications in food and feed testing. However, the concepts, terms, and considerations related to this burgeoning field of analytical testing need to be propagated for the benefit of those associated with academic research, commercial development, or official control. This paper addresses frequently asked questions regarding terminology in connection with NTMs. The widespread development and adoption of these methods also necessitate the need to develop innovative approaches for NTM validation, i.e., evaluating the performance characteristics of a method to determine if it is fit-for-purpose. This work aims to provide a roadmap for approaching NTM validation. In doing so, the paper deliberates on the different considerations that influence the approach to validation and provides suggestions therefor., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)

A proficiency test (PT) program for determination of total As in apple juice samples was conducted by the Food Emergency Response Network (FERN) laboratories. An analytical method using inductively coupled plasma (ICP)-MS was validated for this project. The LOD and LOQ were determined to be 0.315 and 2.32 ng/g, respectively. A total of eight apple juice samples were sent to 38 FERN laboratories, and results were statistically evaluated according to ISO 13528:2005. The total As concentrations in the PT samples reported by the participating laboratories were very close to those obtained in the homogeneity and stability tests. The reproducibility, repeatability, interlaboratory, and intralaboratory variability results led to 69% of participating laboratories being rated as satisfactory using the widely accepted Izl score

Background: To improve prognosis of patients with colorectal cancer, powerful blood-based biomarkers enabling for early detection are needed. As genome-wide DNA hypomethylation is associated with carcinogenesis, and cell-free DNA, thought to be of tumor origin, is found in the circulation of patients with cancer, we investigated the relevance of 5-methylcytosine-modified DNA present in cell-free circulating nucleosomes as a serum biomarker using a convenient enzyme-linked immunosorbent assay (ELISA) technique., Materials and Methods: Serum samples from 90 individuals [24 with colorectal cancer (CRC), 10 with benign colorectal diseases (BCD) and 56 healthy controls (HC)] were tested for the differential diagnostic performance of a novel ELISA for nucleosome-bound methylated DNA. Methodical features, including intra- and interassay imprecision, were tested using serum pools. To minimize interassay variability, values were transformed to adjusted optical densities and robust statistics were applied for clinical evaluation. Findings were later re-evaluated on a set of 113 patients (49 CRC, 26 BCD and 38 HC)., Results: Intra- and interassay reproducibility were 3.4% and 15.3%, respectively. Levels of circulating methylated DNA were significantly decreased in CRC and BCD when compared to HC (p<0.05), although there was no difference between BCD and CRC. For discrimination of CRC from HC, the area under the curve in receiver operating characteristic curve was 0.78 and sensitivities were 33% at 95% specificity and 75% at 70% specificity, respectively. The findings were generally confirmed when validated in the second set of patients., Conclusion: Reduced methylation of DNA on circulating nucleosomes detected by ELISA can potentially serve as a diagnostic tool in patients with CRC.